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This paper presents investigation of surface veracity of Wire EDM machined surfaces of Al / ZrO 2 (p) - MMC obtained utilizing the optimal parametric combinations. The effect of process parameters on the desired performance characteristics, i.e., minimum spark gap (SG), maximum material removal rate (MRR) and minimum surface roughness [SR( R a & R t )], is also presented. The second-order numerical expressions developed by response surface methodology (RSM) are used as a function in.M file. Genetic Algorithm and Direct Search Toolbox of MATLAB ® are utilized to identify the multi-objective optimum set of the process parameters for the desired performance characteristics. In the present paper, surface veracity aspects that include surface defects and thickness of recast layer are investigated for the machined surfaces obtained after Wire EDM to achieve the desired optimum performance characteristics. From the investigation, it can safely be concluded that for the Wire EDM of Al / ZrO 2 (p) - MMC s, lower parameter setting values of pulse width and short pulse time along with higher parameter setting value of time between pulses are desirable from the view point of good surface veracity of the machined surfaces as well as to obtain low average recast layer thickness ( Rl tavg ). The Rl tavg decreases as weight fraction of ZrO 2 (p) increases in Al / ZrO 2 (p) - MMC from 5 to 15%. The investigation of surface veracity of the Wire EDM obtained surfaces will provide the significant guidelines to the production engineers to plan the need of subsequent operations to improve the surface veracity and further the life of the products fabricated using these MMCs. [ABSTRACT FROM AUTHOR]